How much total will you tip the building staff this year at the holidays?

Nothing

Less than $250

Around $250 to $500

Around $500 to $750

Around $750 to $1,000

Around $1,000 to $1,500

Around $1,500 to $2,000

Around $2,000 to $2,500

More than $2,500

Dear Sam: I’ve been living as a roommate in a rent-stabilized apartment that I found on Craigslist, and am thinking of suing for a rent overcharge. It’s an alleged two-bedroom, but one of the rooms is makeshift with no window. And my roommate, who’s the primary leaseholder, charges me more than half the rent. Is this legal?

"What the roommate is doing violates the rent stabilization code, which limits the rent that the tenant can charge to their proportionate share," Himmelstein explains. "The calculation is pretty simple: take the rent and divide it by the number of tenants and roommates. It doesn't matter how much space you occupy [or if someone has a bigger room]."

This means you are indeed within your rights to sue your roommate to recover the extra money you've splashed out, but unlike an overcharge case with a landlord, you're just entitled to the excess rent you've been paying, not triple damages. If your roommate has been charging you so much that you're actually paying more than the legal rent, the situation is more serious, though, as their actions could be considered profiteering. "If the tenant is paying a total of $2,000 but charging the roommate $2,500, that could cause the tenant to potentially lose the apartment, whereas a straightforward roommate overcharge would not," Himmelstein says.

The situation is complicated further by the fact that your "makeshift [room] with no window" isn't considered a legal bedroom, meaning that either the landlord or your roommate has been misrepresenting the apartment. "The tenant shouldn't even be renting out that room at all," says Himmelstein. "You could make the argument that you don't have a habitable room."

That said, before you start filing lawsuits and making calls to the landlord, you'd be wise to consider what you want out of the situation. "I'm not sure it would make much sense to rat out your roommate to the landlord, because in the profiteering scenario at least, you could both lose the apartment," says Himmelstein. While your roommate can't legally kick you out without filing an eviction case in Housing Court if you've been in the apartment for more than 30 days, "I've seen these situations before where you have a tenant and a roommate feuding in an apartment and it gets really ugly and uncomfortable," says Himmelstein. Either confront your roommate to work out a new financial arrangement between the two of you, or go ahead and sue—but if you value your sanity, start looking for another place to live.